/*
 * oauth2-oidc-sdk
 *
 * Copyright 2012-2021, Connect2id Ltd and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the
 * License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed
 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */

package com.nimbusds.openid.connect.sdk.assurance.evidences.attachment;


import java.util.LinkedList;
import java.util.List;
import java.util.Objects;

import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;

import com.nimbusds.oauth2.sdk.ParseException;
import com.nimbusds.oauth2.sdk.util.JSONArrayUtils;


/**
 * Identity evidence attachment.
 *
 * <p>Related specifications:
 *
 * <ul>
 *     <li>OpenID Connect for Identity Assurance 1.0, section 5.1.2.
 * </ul>
 */
public abstract class Attachment {
        
        
        /**
         * The attachment type.
         */
        private final AttachmentType type;
        
        
        /**
         * The optional description.
         */
        private final String description;
        
        
        /**
         * Creates a new attachment with the specified description.
         *
         * @param type        The type. Must not be {@code null}.
         * @param description The description, {@code null} if not specified.
         */
        protected Attachment(final AttachmentType type, final String description) {
                Objects.requireNonNull(type);
                this.type = type;
                this.description = description;
        }
        
        
        /**
         * Returns the type of this attachment.
         *
         * @return The type.
         */
        public AttachmentType getType() {
                return type;
        }
        
        
        /**
         * Returns the description.
         *
         * @return The description string.
         */
        public String getDescriptionString() {
                return description;
        }
        
        
        /**
         * Returns a JSON object representation of this attachment.
         *
         * @return The JSON object.
         */
        public JSONObject toJSONObject() {
                
                JSONObject o = new JSONObject();
                if (getDescriptionString() != null) {
                        o.put("desc", getDescriptionString());
                }
                return o;
        }
        
        
        @Override
        public boolean equals(Object o) {
                if (this == o) return true;
                if (!(o instanceof Attachment)) return false;
                Attachment that = (Attachment) o;
                return Objects.equals(description, that.description);
        }
        
        
        @Override
        public int hashCode() {
                return Objects.hash(description);
        }
        
        
        /**
         * Casts this attachment to an embedded attachment.
         *
         * @return The embedded attachment.
         *
         * @throws ClassCastException If the cast failed.
         */
        public EmbeddedAttachment toEmbeddedAttachment() {
                
                return (EmbeddedAttachment) this;
        }
        
        
        /**
         * Casts this attachment to an external attachment.
         *
         * @return The external attachment.
         *
         * @throws ClassCastException If the cast failed.
         */
        public ExternalAttachment toExternalAttachment() {
                
                return (ExternalAttachment) this;
        }
        
        
        /**
         * Parses an identity evidence attachment from the specified JSON
         * object.
         *
         * @param jsonObject The JSON object. Must not be {@code null}.
         *
         * @return The identity evidence attachment.
         *
         * @throws ParseException If parsing failed.
         */
        public static Attachment parse(final JSONObject jsonObject)
                throws ParseException {
                
                if (jsonObject.get("content") != null) {
                        return EmbeddedAttachment.parse(jsonObject);
                } else if (jsonObject.get("url") != null) {
                        return ExternalAttachment.parse(jsonObject);
                } else {
                        throw new ParseException("Missing required attachment parameter(s)");
                }
        }
        
        
        /**
         * Parses a list of identity evidence attachments from the specified
         * JSON array.
         *
         * @param jsonArray The JSON array, {@code null} if not specified.
         *
         * @return The list of identity evidence attachments, {@code null} if
         *         not specified.
         *
         * @throws ParseException If parsing failed.
         */
        public static List<Attachment> parseList(final JSONArray jsonArray)
                throws ParseException {
                
                if (jsonArray == null) {
                        return null;
                }
                
                List<Attachment> attachments = new LinkedList<>();
                for (JSONObject attachmentObject: JSONArrayUtils.toJSONObjectList(jsonArray)) {
                        attachments.add(Attachment.parse(attachmentObject));
                }
                return attachments;
        }
}